A tape cutter for cutting a printed portion of a band-shaped printing tape is known (see JP-A-2003-237155).
This type of tape cutter includes a slide cutter which cuts the printing tape, a cutter driving mechanism which allows the slide cutter to carry out cutting, a tape pressing member which presses the printing tape against a receiving member provided on a cutter frame prior to the cutting by the slide cutter, a coil spring disposed between the slide cutter and the tape pressing member to urge the cutter and the tape pressing member in directions away from each other, and a return spring whose one urging end is hooked to the slide cutter to return the slide cutter from a cutting position to a standby position.
Upon the start of the cutting by the slide cutter with the aid of the cutter driving mechanism, the tape pressing member shifts together with the slide cutter to press the printing tape. In this condition, the slide cutter further shifts while compressing the coil spring, and cuts the printing tape. After the cut of the printing tape, the return spring starts returning action to shift the slide cutter toward the standby position along with expansion of the coil spring. With further shift of the sliding cutter, the tape pressing member comes into engagement with the slide cutter, and returns to an original standby position together with the slide cutter.
According to the known tape cutter having this structure, the cutter driving mechanism shifts the slide cutter (and the tape pressing member) in the cutting direction while resisting the forces of the return spring and the coil spring. In this case, the cutter driving mechanism drives the slide cutter to allow the cutting operation by the cutter while resisting practically two spring forces of the return spring functioning as a tension spring and the coil spring functioning as a compression spring, the two springs of which are connected in parallel with each other. Thus, an output torque of a power source (motor) of the cutter driving mechanism is set large enough to resist the two spring forces of the springs connected in parallel with each other and the cutting resistance produced by the slide cutter. This condition increases the size of the power source (motor), or requires a rigid power transmission system as well as a complicated gear train.